1. Field of the Invention
This invention relates to an improved rack for supporting articles placed thereon. This invention is especially suited to support heavier objects while keeping the rack itself as light as possible.
2. Description of Prior Art
Racks are often used whenever it is desirable to have a platform on which various articles can be supported. Racks are often fabricated of common round wire rod with a rectangular structural perimeter member and a number of smaller support members attached to either the front and rear members of the structural perimeter member (longitudinal direction) or to opposite sides of the structural perimeter member (transverse direction). Generally these racks are supported by resting the rack on its structural perimeter member.
A common problem encountered by rack users is that, as the size of the rack increases and as the weight of articles placed thereon increases, the rack itself suffers either or both a longitudinal deflection (a deflection from front to rear) or a transverse deflection (a deflection from side-to-side). Traditional methods of overcoming this problem include the utilization of larger structural perimeter members and support members. Frequently additional side-to-side structural members are T welded to the inside edges of the structural perimeter member to increase strength by adding more structure to the rack. U.S. Pat. Nos. 2,110,726 and 2,225,991 show one application of such an approach. Additionally, longitudinal structural members are spaced across and welded to the bottom of the front and rear sides of the structural perimeter member and the transverse structural members where they intersect to form a grid. While these methods of increasing rack strength do work, they also add considerable weight to the rack which makes it correspondingly more difficult to handle.
Of the rack designs with which I am familiar, none utilize the spaced double-bar construction as embodied in this invention. However, British Pat. No. 929,071 does show a pair of rectangular wire frames separated by spaced parallel wires but teaches that the sides of such racks are resilient for insertion into mating brackets. At best, any interpretation would recognize only limited deflection resistance in one direction, the transverse direction.
Additional techinques used to add strength to large racks include the attachment of metal bars of rectangular cross section, with the larger dimension parallel to the plane of deflection of the rack and positioned against the structural perimeter member in perpendicular relation to the support members. Another rack design uses metal balls as spacing elements between the structural perimeter member and a structural member to develop added strength in the correspondeing direction. However, both of these approaches require the use of nonstandard forms of materials, specifically metal bars and metal balls, which necessarily require special handling during fabrication.
Another deficiency of the prior art devices is that their design requires the use of a combination welding techniques in the fabrication of the rack rather than the use of a standardized welding technique which would facilitate the construction of the rack. Conventional racks require combination of butt welds, T welds, and lapp welds, whereas my invention uses almost exclusively the lapp weld.
The prior art devices with which I am familiar do not provide adequate strength and resistance to deflection for both the longitudinal and transverse directions in a light weight rack design. Further, I am not aware of any prior art device which incorporate the spaced double-bar design with other than metal ball spacers. Nor have I observed any rack design which utilizes the elements of the rack in multi-functional capacities. Those racks which do provide additional strength features are difficult to fabricate because of the use of nonstandard materials. Also, prior art racks have not standardized their method of welding the various members of the rack to one another.